According to Charlotte Mason, a "living book" is usually written by one person who has a passion for the subject and writes in conversational or narrative style. The books pull you into the subject and involve your emotions, so it's easy to remember the facts and events. Living books make the subject "come alive". They can be contrasted to dry writing, like what is found in most encyclopedias and textbooks, which basically lists informational facts in summary form. You might be surprised to find that living books are available in most school subjects. (https://simplycharlottemason.com/faq/livingbook/)
The above pictured living book is a great children's book with beautiful pictures. I read this book with my youngest son and then found the lyrics to the song "Rockin' Robin" and played the song for him and taught him the words, so we combined this book and a song for science and music.
As for reading aloud to your child(ren), not only is it a fun activity, but it is an opportunity to increase the bond between you and your chidl(ren) and to create lasting memories. I read books aloud to all of my boys all the way to their high school graduation, and my oldest says it's still one of his favorite homeschool memories. I always do my best to change my voice for each character's dialogue lines, and even at the high school level, my boys enjoyed our read aloud time. My oldest also said, when he was home on school breaks from college, if he was doing something in the same or next room where I was reading aloud to our youngest son, he would become distracted from his own activity and find himself listening to me.
A favorite read aloud memory of my two older boys is my reading of "Huckleberry Finn" by Mark Twain. That book drove me crazy, and I would get frustrated when the bad guys kept showing up wherever Huck went for quite some time. The boys found that quite funny.
